Method, Base Station and a User Equipment for Selecting a Set of Beams to be Monitored by Said UE

ABSTRACT

A method of selecting a set of beams to be monitored by a User Equipment (UE) in a telecommunication network comprises the steps of receiving measurement data comprising measurements of qualities of beams observed by said UE, where said beams originate from at least one access node (AN) to the UE and from at least one other AN to the UE; retrieving at least one measurement data from a particular UE that matches the received measurement data, where the historical database comprises historical measurement data comprising measurements of qualities of beams observed by UE&#39;s in said telecommunication network over time; selecting a set of beams to be monitored by said UE based on the retrieved measurement data and based on subsequent measurement data of the particular UE over time in the historical database; and transmitting said selected set of beams to be monitored to said UE.

TECHNICAL FIELD

The present invention generally relates to selecting a set of beams tobe monitored and, more specifically, to selecting the beams based onhistorical measurement data of qualities of beams previously observed byUser Equipment.

BACKGROUND

Extremely high frequency, EHF, is the International TelecommunicationsUnion, ITU, designation for the band of radio frequencies in theelectromagnetic spectrum from 30 to 300 gigahertz, GHz. Radio waves inthis band have wavelengths from ten to one millimetre, giving it thename millimetre band or millimetre wave, sometimes abbreviated MMW ormmW.

These frequency bands are envisioned to be used as the correspondingspectrum is not as occupied as compared to frequently used frequencybands, for example frequency bands below 6 GHz, thereby improving systemcapacity. Propagation effects are, however, severe in these frequencybands. For example, signal quality decays quickly with distance and, forexample, diffraction, penetration and/or reflection losses areconsidered to be high.

One of the proposed advancements in this area is to use beamforming withnarrow beams and high directivity using very-large antenna arrays,namely massive Multiple-Input-Multiple-Output, MIMO, antennas.

Beamforming or spatial filtering is a signal processing technique usedin arrays for directional signal transmission or reception. This isachieved by combining elements in an antenna array in such a way thatsignals at particular angles experience constructive interference whileothers experience destructive interference. Beamforming can be used atboth the transmitting and receiving ends in order to achieve spatialselectivity. The improvement compared with omnidirectionalreception/transmission is known as the directivity of the array.

Following the above, it may be advantageous if measurement and reportingof multiple narrow beams, or simply put beam management, is efficientlyaddresses so that access nodes, AN's, are able to, for example, keep thesignal quality experienced on the user side, i.e. at the User Equipment,UE, above a predetermined threshold.

It is noted that for the next generation of radio technology, namely 5Gnew radio, NR, 3GPP briefly describes a set of procedures to beammanagement indicating that the procedure to intra/inter AN's beam switchcan use a smaller set of beams compared to the joint beam space.

In Long Term Evolution, LTE, neither massive MIMO antennas nor mm-Wavebands are supported. Thus, the LTE solution only supports the managementof the entire beam space. The use of such a solution to manage severalnarrow beams would prohibitively increase the signalling burden.

Currently deployed solutions are based on beam training. That is, thebeams, or the set of beams, to be used for transmission is determinedbased on UE measurements on previously selected beams. Thesemeasurements may, for example, be out-of-date and this can cause aspatial misalignment that may lead to beam failure.

SUMMARY

It is an object to provide for methods of selecting beams to bemonitored by a User Equipment, UE, thereby, amongst other, reducingoverhead signalling in a telecommunication network.

It is another object to provide for a base station function, a UserEquipment, UE, as well as a non-transitory computer-readable storagemedium involved within the methods as presented.

In a first aspect, there is provided a method of selecting a set ofbeams to be monitored by a User Equipment, UE, in a telecommunicationnetwork, said telecommunication network comprising a Base Station, BS,function coupled to at least one Access Node, AN, serving said UE

The method comprising the steps of receiving, by said BS function, fromsaid UE, measurement data comprising measurements of qualities of beamsobserved by said UE, wherein said beams originate from at least said atleast one AN to said UE, retrieving, by said BS function, in ahistorical database, at least one measurement data from a particular UEthat is most similar to the received measurement data, wherein thehistorical database comprises historical measurement data comprisingmeasurements of qualities of beams observed by UE's in saidtelecommunication network over time, selecting, by said BS function, aset of beams to be monitored by said UE based on said retrieved at leastone measurement data from said particular UE and based on subsequentmeasurement data of said particular UE over time in said historicaldatabase, and transmitting, by said BS function, said selected set ofbeams to be monitored to said UE.

The method is at least based on the insight that historical measurementsmay be taken into account in determining which beams the UE shouldmonitor. The historical database may be empty at first, and may befilled during runtime. As such, measurements related to qualities ofbeams observed by UE's may be stored in the historical database, and arelationship in time between those measurements may be stored as well.The above entails that the database comprises measurements of qualitiesof beams observed by UE's over time.

One of the advantageous of the above described method is that it is morelikely that good quality beams are selected for the UE, as the selectingprocess is based on previous measurements. The previous measurements mayeven be related to the same UE. This enables the selecting process totake into account movement habits of the particular UE.

For example, it can be detected that a particular UE often travelsbetween two geographical locations, i.e. once a day, once a week oranything alike. Such a habit can be detected in the historical database.Patterns in previous measurements of that particular UE may reflect sucha habit, and these patterns may be detected, and used, for selecting thebeams to be monitored. As such, the BS function is able to properlyestimate the beams that are to be used to that particular UE.

It is noted that, in accordance with the present disclosure, the beamsmay originate from a massive Multiple-Input-Multiple-Output, MIMO,transmission technique. Each of the Access Nodes, AN's, may comprise aplurality of array antenna's and/or multiple antenna's for directivitypurposes.

Massive MIMO may entail systems that use antenna arrays with, forexample, a few hundred of antennas, simultaneously serving many tens ofUE's in the same time-frequency resource. The basic aspect of massiveMIMO is to reap all the benefits of conventional MIMO, but on a greaterscale.

Each antenna may be small, preferably fed via an optical or electricdigital bus. Massive MIMO relies on spatial multiplexing that in turnrelies on the base station, i.e. the base station function, havingchannel knowledge, both on the uplink and the downlink. On the uplink,this may be accomplished by having the terminals send pilots, based onwhich the base station estimates the channel responses to each of theterminals.

In accordance with the present disclosure, the BS function receivesmeasurement data comprising measurements of qualities of beams observedby the UE. These beams originate from at least one Access Node. The UEmay observe beams from a plurality of Access Nodes, AN's,simultaneously. These measurements relate to the qualities of the beams,for example the signal-to-noise ratios, or anything alike.

The BS function will then retrieve, in a historical database, at leastone measurement data from a particular UE that matches the receivedmeasurement data. This means that the function searches the database forany historical measurement data that best resembles the receivedmeasurement data. For example, the received measurement data mayindicate a particular order of the beams, wherein the beams are orderedby their measured quality. The beam having the highest quality is putfirst, the beam having the second highest quality is put second, etc.The BS function will then search the historical database for measurementdata comprising a same, or similar, order of beams.

The retrieved measurement data is associated, in the historicaldatabase, with subsequent measurement data. The historical measurementdata is related to a measurement made by a particular UE at a certainpoint in time T1. That same particular UE has made another measurementat a subsequent point in time T2. The corresponding measurement data ofthis subsequent measurement is associated with the retrieved measurementdata in the historical database. The corresponding measurement data isthen used for the selection purpose. That is, the BS function selects aset of beams, from the corresponding measurement data, to be monitoredby the UE.

In a final step, the selected set of beams to be monitored istransmitted to the UE.

In accordance with the present disclosure, the BS function may beimplemented in a base station, in a network node, in the cloud oranything alike.

In accordance with the present disclosure, the measurements may beperformed on longer time scales such as averaged over a radio frame or aplurality of radio frames, e.g. 50-100 milliseconds. However, theexamples described herein are also applicable for traffic measurementsperformed on shorter time scale such as on symbol, time slot or subframe basis or even on a shorter time scale.

The selected set of beams may also be used, by the BS function, for aparticular radio operation task. A radio operation task is, for example,any of a cell change between two cells, scheduling or resourceassigning, load balancing, network planning or tuning of networkparameters, controlling uplink and/or downlink power, avoiding and/ormitigating interference, etc.

The BS function may receive the measurement data from the UE in any oneor more of the following manners: periodically, on event triggeredbasis, e.g. when a certain measurement exceeds a threshold or fallsbelow a threshold, and in response to a request sent by the BS functionto the UE.

One of the advantages of the presented method is that the controlchannel between the UEs and the access nodes is relieved. That is,compared to the prior art, the UE is presented with a set of beams to bemonitored, wherein the set of beams is a subset of all the beams thatare available for the UE to be monitored. As such, the control channelonly needs to be used for exchanging information with respect to thatparticular subset of beams.

Another advantage is that the UE does not need to monitor all the beamsthat are available for the UE to be monitored. The UE is presented witha subset of beams. This received unnecessary processing power by the UE.

In an example, the received measurement data comprising measurements ofqualities of beams observed by said UE comprises:

-   -   a signal-to-noise ratio for each of said beams;    -   a Received Signal Strength Indicator, RSSI, for each of said        beams;    -   a Reference Signal Received Power, RSRP for each of said beams;    -   a Reference Signal Received Quality, RSRQ, for each of said        beams.

In another example, the method further comprises the step of:

-   -   storing, by said BS function, said received measurement data in        said historical database.

The advantage of this example is that the historical database is filledadequately. As mentioned before, the historical database may be emptyinitially. The historical database may then be filled with all kinds ofmeasurement data generated by UEs present in the telecommunicationnetwork. An increasing amount of measurement data present in thehistorical database increases the likelihood that a received measurementdata matches any of the historical measurement data present in thedatabase.

In a further example, the method further comprises the steps of:

-   -   determining, by said BS function, based on said retrieved at        least one measurement data from said particular UE and based on        subsequent measurement data of said particular UE over time in        said historical database, that said UE is to be handed over to a        different AN in said telecommunication network;    -   performing, by said BS function, a handover of said UE to said        determined different AN in said telecommunication network.

In a further example, said step of transmitting, by said BS function,said selected set of beams to be monitored to said UE further comprises:

-   -   transmitting, by said BS function, a frequency parameter        indicating to said UE how many measurements for said selected        set of beams are to be performed by said UE.

Here, the BS function determined how often the measurements are to beperformed by the UE.

In a second aspect of the present disclosure, there is provided a methodof monitoring a set of beams, by a User Equipment, UE, in atelecommunication network served by an Access Node, AN, said methodcomprising the steps of:

-   -   receiving, by said UE, a set of beams to be monitored;    -   measuring, by said UE, qualities of said received set of beams        to be monitored;    -   selecting, by said UE, a subset of said set of beams based on        said measured qualities of said received set of beams, and    -   transmitting, by said UE, measurement data comprising        measurements of qualities of said subset of beams to said AN.

The expressions, i.e. the wording, of the different aspects comprised bythe method and devices according to the present disclosure should not betaken literally. The wording of the aspects is merely chosen toaccurately express the rationale behind the actual functioning of theaspects.

In accordance with the present disclosure, different aspects applicableto the above mentioned examples of the methods, including the advantagesthereof, correspond to the aspects which are applicable to the basestation as well as the User Equipment.

In a third aspect, there is provided a network node, for example a BaseStation, BS, arranged for selecting a set of beams to be monitored by aUser Equipment, UE, in a telecommunication network, said BS beingcoupled to at least one Access Node, AN, serving said UE, said BScomprising:

-   -   receive equipment arranged for receiving, from said UE,        measurement data comprising measurements of qualities of beams        observed by said UE, wherein said beams originate from said at        least one AN to said UE, and originate from at least another AN        in said telecommunication network to said UE;    -   retrieve equipment arranged for retrieving in a historical        database, at least one measurement data from a particular UE        that matches the received measurement data, wherein the        historical database comprises historical measurement data        comprising measurements of qualities of beams observed by UE's        in said telecommunication network over time,    -   select equipment arranged for selecting a set of beams to be        monitored by said UE based on said retrieved at least one        measurement data from said particular UE and based on subsequent        measurement data of said particular UE over time in said        historical database;    -   transmit equipment arranged for transmitting said selected set        of beams to be monitored to said UE.

In an example, said received measurement data comprising measurements ofqualities of beams observed by said UE comprises:

-   -   a signal-to-noise ratio for each of said beams;    -   a Received Signal Strength Indicator, RSSI, for each of said        beams;    -   a Reference Signal Received Power, RSRP for each of said beams;    -   a Reference Signal Received Quality, RSRQ, for each of said        beams.

In a further example, the BS further comprises:

-   -   store equipment arranged for storing said received measurement        data in said historical database.

In yet another example, the BS further comprises:

-   -   process equipment arranged for determining, based on said        retrieved at least one measurement data from said particular UE        and based on subsequent measurement data of said particular UE        over time in said historical database, that said UE is to be        handed over to a different AN in said telecommunication network,        and for performing a handover of said UE to said determined        different AN in said telecommunication network.

In an example, the transmit equipment is further arranged for:

-   -   transmitting a frequency parameter indicating to said UE how        many measurements for said selected set of beams are to be        performed by said UE.

In a fourth aspect, there is provided a User Equipment, UE, arranged formonitoring a set of beams in a telecommunication network, said UE beingarranged to be served by an Access Node in said telecommunicationnetwork, said UE comprising:

-   -   receive equipment arranged for receiving a set of beams to be        monitored;    -   measure equipment arranged for measuring qualities of said        received set of beams to be monitored;    -   select equipment arranged for selecting a subset of said set of        beams based on said measured qualities of said received set of        beams, and    -   transmit equipment arranged for transmitting measurement data        comprising measurements of qualities of said subset of beams to        said AN.

In a fifth aspect, there is provided a Base Station, BS, for selecting aset of beams to be monitored by a User Equipment, UE, in atelecommunication network, said BS being coupled to at least one AccessNode, AN, serving said UE, said BS comprising:

-   -   receive module for receiving, from said UE, measurement data        comprising measurements of qualities of beams observed by said        UE, wherein said beams originate from said at least one AN to        said UE, and originate from at least another AN in said        telecommunication network to said UE;    -   retrieve module for retrieving in a historical database, at        least one measurement data from a particular UE that matches the        received measurement data, wherein the historical database        comprises historical measurement data comprising measurements of        qualities of beams observed by UE's in said telecommunication        network over time,    -   select module for selecting a set of beams to be monitored by        said UE based on said retrieved at least one measurement data        from said particular UE and based on subsequent measurement data        of said particular UE over time in said historical database;        transmit module for transmitting said selected set of beams to        be monitored to said UE.

In a sixth aspect, there is provided a User Equipment, UE, formonitoring a set of beams in a telecommunication network, said UE beingarranged to be served by an Access Node in said telecommunicationnetwork, said UE comprising:

-   -   receive module for receiving a set of beams to be monitored;    -   measure module for measuring qualities of said received set of        beams to be monitored;    -   select module for selecting a subset of said set of beams based        on said measured qualities of said received set of beams, and    -   transmit module for transmitting measurement data comprising        measurements of qualities of said subset of beams to said AN.

In a seventh aspect, there is provided a computer program product,comprising a readable storage medium, comprising instructions which,when executed on at least one processor, cause the at least oneprocessor to carry out the method according to any of the examples asprovided above.

The above-mentioned and other features and advantages of the disclosurewill be best understood from the following description referring to theattached drawings. In the drawings, like reference numerals denoteidentical parts or parts performing an identical or comparable functionor operation.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an example of how measurement data can be obtained by aUser Equipment, UE.

FIG. 2 shows an example of an illustration displaying a basic aspect ofthe present disclosure.

FIG. 3 shows a part of a telecommunication network in accordance withthe present disclosure.

FIG. 4 shows a structure in which the measurement data is stored in thehistorical database.

FIG. 5 shows an example of a method in accordance with the presentdisclosure.

FIG. 6 shows another example of a method in accordance with the presentdisclosure.

FIG. 7 shows an example of a Base Station function in accordance withthe present disclosure.

FIG. 8 shows an example of a User Equipment in accordance with thepresent disclosure.

DETAILED DESCRIPTION

FIG. 1 shows an example 1 of how measurement data can be obtained by aUser Equipment, UE. The present example is 1 is explained with respectto a selection of a set of beams to be monitored for a particular UE.

The beam selection procedure for beam tracking may be described asfollows. A Base Station, BS, function serving the particular UEdetermines a set of beams from at least one directly connected AccessNode, AN, and another set of beams from at least one AN belonging to oneneighbor BS. The serving BS relies on available historical statistics ofUEs and on measurement data from its served UE to determine these set ofbeams that keep an adequate spatial alignment of these beams with itsserved UE.

In this example, the served UE measures the quality of the receivedsignal for every determined beam during a determined period T′, say anumber of time instants when measurement is considered, within adetermined beam reporting period T≥T′, when the served UE reports themeasurement data to its serving BS with respect to a portion, say M, ofthe beams received above a certain predefined threshold.

The number of beams that can be monitored by the UE may be greater thanthe amount of feedback that the UE is able to report to the BS function,i.e. M. During the measuring period T′, the UE may store all kinds ofquality values of detected and decoded beams for all the beams in thedetermined set. At the end of T′, the UE may select the M beams to bereported, which are the ones with highest signal quality during the T′measured time instants. In the current scenario, M is fixed and dependson the capability of the UE.

FIG. 1 shows the monitored beams, which are the six beams as indicatedwith AN2 a, AN 2 b and AN1 b. Further, M=3, and T′ comprises 5 timeslots. The UE may store all the values, and after T′, the UE may selectthe highest three values it can find in the table, for example the onesas indicated with the stars in the grid. The UE then reports to the BSthe corresponding measurement data, i.e. the qualities of the beams, forthe whole time T′. Other means of selecting the M highest values arealso possible. For instance, the UE can select the M highest valuesafter a pre-processing, e.g. time averaging, of all the stored values.

The serving BS function receives measurement data from its served UE.The BS function then searches in the historical database for a number ofmost likely, or most similar, samples, i.e. measurement data, to thereceived measured measurement data. An estimate of metric values,related to the measurement data, in a few time instants ahead and forall relevant beams can then be obtained based on the most similarsamples. By using the estimated metric values, the serving BS functioncan determine a set of beams from its ANs that provide an improvedspatial alignment to the UE for some time instants ahead.

This may result in, for example, an intra BS beam handover. Furthermore,also based on the estimated metric values, the serving BS may determineanother set of beams from ANs of at least a neighbor BS that canpotentially provide the best spatial alignment to its served UE. Thismay further yield an inter-BS beam handover. Furthermore, the serving BSmay determine the values of T′, T and may select M. At last, the servingBS informs its served UE the set of selected beams to be monitored andthe determined parameter values.

FIG. 2 shows an example of an illustration 51 displaying a basic aspectof the present disclosure.

The illustration 52 provides for a basic overview of the steps that aretaken in accordance with the present disclosure. Beam measurements areperformed by the UE 112, and those beam measurements are provided 302 tothe Base station function 102.

The base station function 102 may store 52 these measurement, i.e. themeasurement data in a historical database for further use. Further, thebase station function 102 retrieves at least one measurement data fromthe same historical database, wherein the at least one measurement databest matches the measurement data received from the UE 112. Based on theretrieved measurement data, the base station function 112 selects 304particular beams for which the UE 112 should perform measurement insubsequent time periods. The selected beams are provided 305 to the UE112.

The communication between the UE 112 and the base station function 102is provided over an air interface, i.e. wirelessly. Typically, a controlchannel message over a control channel is utilized. Reducing the amountof beams for which the UE 112 is to perform quality measurements alsoreduces the amount of signalling between the UE 112 and the base stationfunction 102. This, thus, improves the efficiency of thetelecommunication network.

It is further noted that the selected set of beams are provided to theUE 112. In practice, it may be identifiers of the selected beams thatare provided to the UE 112, not the beams themselves. As such,transmitting a set of beams may be interpreted as transmittingidentifications of the selected beams to the UE 112.

FIG. 3 shows a part of a telecommunication network 101 in accordancewith the present disclosure.

The telecommunication network 101 comprises two base stations 103, 111,wherein the first base station 103 has two access nodes, AN's, 104, 105,and wherein the second base station 111 has another two AN's 109, 110.

A Base Station, BS, function 102 is provided, which BS function 102 isarranged to perform beam management for UE tracking. It is noted thatthe BS function 102 may be implemented in a Base station 103, 111 or anyother node in the telecommunication network. The BS function 102 may beprovided as a cloud service, wherein the processing is performed in thecloud.

Here, a User Equipment, UE, 112 is shown which is arranged to travel aparticular trajectory 113. One of the aspects of the present disclosureis that the trajectory may be estimated based on previous measurementsperformed by that same, or any other, UE. In this particular scenario,the UE 112 is arranged to monitor six beams 106, 107, 108. The beams asreferenced to with reference numeral 106 originate from the AN withreference numeral 105. The beam as referenced to with reference numeral107 originates from the AN with reference numeral 110. The beams asreferenced to with reference numeral 108 originate from the AN asreferenced to with reference numeral 109.

The UE 112 will monitor each of these beams 106, 107, 108 during apredefined time period, for example a plurality of time slots or aplurality of symbols. This means that the UE 112 may performed qualitymeasurements with respect to those beams 106, 107, 108. The UE 112 willthus generate measurement data, wherein the measurement data is relatedto the quality of the beams 106, 107, 108 that have beenmonitored/measured.

In accordance with the present disclosure, the quality of the beams maybe measured in terms of signal to noise ratio or any other type ofmeasurement. Further, the measurement for the qualities of the beams106, 107, 108 may be performed in parallel, substantially in parallel,or subsequently to each other.

The UE 112 may, subsequently, select a subset of the beams 106, 107, 108that have been monitored. In this particular example, the UE may selectthe beams as referenced to with reference numeral 106. Alternatively,the UE 112 may provide all measurement data, i.e. from all the six beams106, 107, 108, to the AN 105 via which it is connected to the basestation as indicated with reference numeral 103.

The BS function 102 will then retrieve, in a historical database 114, atleast one measurement data from a particular UE that matches themeasurement data from the UE 112. The historical database 114 compriseshistorical measurement data comprising measurements of qualities ofbeams observed by UE's in the telecommunication network over time.

As such the measurement data provided by the UEs in thetelecommunication network may be stored in the historical database 114.The measurement data may be provided with a time stamp, or any othermeta data that indicated the moment when the corresponding measurementwas made. This allows for patterns to be detected in the historicaldatabase. Measurement data can be associated with each other based onthe time stamps that are provided and based on, for example,identifications of the UEs that made those particular correspondingmeasurements.

The BS function 102 then selects a set of beams to be monitored by theUE 112 based on the retrieved at least one measurement data from theparticular UE, and based on subsequent measurement data of theparticular UE over time in the historical database.

In this particular scenario, the trajectory 113 may be estimated basedon previous measurements of that particular UE that are stored in thehistorical database 114. That particular information may be used, in thetelecommunication network, to initiate a handover of the UE 112, forexample a intra BS handover or an inter BS handover.

FIG. 4 shows a structure in which the measurement data is stored in thehistorical database.

The measurement data that is stored may be conceptually visualized asdata that is stored using three dimensions 202, 203, 204. The firstdimension, i.e. as indicated with reference numeral 202, is related tothe identification of the beams. The second dimension, i.e. as indicatedwith reference numeral 203, is related to the identification of thesamples. The third dimension, i.e. as indicated with reference numeral204, is related to the time instants.

In accordance with the present disclosure, the BS function retrieves atleast one measurement data from a particular UE that matches thereceived measurement data. This may be accomplished as follows.

The BS function may select one or more slices of the historicaldatabase, wherein the slice is made in the data structure 201 in a planedefined by the dimensions as indicated with reference numerals 202 and204. As such, a particular slice is directed to a single sample, i.e. toa measurement made by a particular UE.

Each of the slices comprises measurement data, i.e. measurements ofqualities of respective beams and a time indication when thosemeasurements were performed. The BS function may thus select one, ormore, of those slices that best resemble(s) the received measurementdata, i.e. the actual measurement performed by the UE.

Based on the selected slice, the BS function may select the beams thathave the highest Signal-to-Noise ratio in the time instants ahead, i.e.in the subsequent time frames in that same slice.

FIG. 5 shows an example of a method 301 in accordance with the presentdisclosure.

The method 301 is directed to the selection of a set of beams to bemonitored by a User Equipment, UE, in a telecommunication network, saidtelecommunication network comprising a Base Station, BS, functioncoupled to at least one Access Node, AN, serving said UE.

The method comprises the step of receiving 302, by said BS function,from said UE, measurement data comprising measurements of qualities ofbeams observed by said UE, wherein said beams originate from said atleast one AN to said UE, and originate from at least another AN in saidtelecommunication network to said UE.

The above entails that the UE has performed quality measurements withrespect to beams that it was requested to monitor. These measurements,or a subset thereof, are provided to the BS function using measurementdata.

In a next step, the BS function retrieves 303, in a historical database,at least one measurement data from a particular UE that matches thereceived measurement data, wherein the historical database compriseshistorical measurement data comprising measurements of qualities ofbeams observed by UE's in said telecommunication network over time.

In accordance with the present disclosure, matching means that the BSfunction finds historical measurement data in the historical databasethat best matches the received measurement data. The historicalmeasurement data subsequent to the matched historical measurement datamay then be used, by the BS function to select a set of beams to bemonitored by the UE which is explained here below.

Thus, in a next step, the BS function selects 304 a set of beams to bemonitored by said UE based on said retrieved at least one measurementdata from said particular UE and based on subsequent measurement data ofsaid particular UE over time in said historical database. As such, theBS function may be able to perform an educated guess about the beamsthat could be of interest for the UE, i.e. the beams that could have thehighest quality for the UE.

In a final step, the BS function transmits said selected set of beams tobe monitored to said UE.

FIG. 6 shows another example of a method 401 in accordance with thepresent disclosure.

The method 401 is directed to the monitoring of a set of beams, by aUser Equipment, UE, in a telecommunication network served by an AccessNode, AN.

The method comprises the steps of:

Receiving 402, by said UE, a set of beams to be monitored;

Measuring 403, by said UE, qualities of said received set of beams to bemonitored;

Selecting 404, by said UE, a subset of said set of beams based on saidmeasured qualities of said received set of beams, and

Transmitting 405, by said UE, measurement data comprising measurementsof qualities of said subset of beams to said AN.

FIG. 7 shows an example of a Base Station function 501 in accordancewith the present disclosure.

Here, the Base Station function 501 is explained with respect to aparticular base station. It is however noted that the Base Stationfunction 501 may also be provided as a service running in the cloud, inany network node, distributed among network nodes, or anything alike.

The Base Station function 501 is arranged for selecting a set of beamsto be monitored by a User Equipment, UE, in a telecommunication network,said BS being arranged to be coupled to at least one Access Node, AN,serving said UE.

The BS function 501 comprises receive equipment 502 arranged forreceiving, from said UE, measurement data comprising measurements ofqualities of beams observed by said UE, wherein said beams originatefrom said at least one AN to said UE.

The BS function 501 further comprises retrieve equipment 505 arrangedfor retrieving in a historical database, at least one measurement datafrom a particular UE that matches the received measurement data, whereinthe historical database comprises historical measurement data comprisingmeasurements of qualities of beams observed by UE's in saidtelecommunication network over time.

The BS function 501 further comprises select equipment 504 arranged forselecting a set of beams to be monitored by said UE based on saidretrieved at least one measurement data from said particular UE andbased on subsequent measurement data of said particular UE over time insaid historical database.

The BS function 501 further comprises transmit equipment 509 arrangedfor transmitting said selected set of beams to be monitored to said UE.

The BS function 501 comprises a control unit 507 and a memory 506, whichcontrol unit 507 is connected to the retrieve equipment 505, the selectequipment 504, the receive equipment 502 and the transmit equipment 509.

Incoming data packets or messages pass through the input terminal 503before they reach the receive equipment 502, or receive module. Outgoingdata packets or messages pass, or are sent, by the transmit equipment509, or a transmit module, via the output terminal 508.

FIG. 8 shows an example of a User Equipment 601 in accordance with thepresent disclosure.

The User Equipment, UE, 601 is arranged for monitoring a set of beams ina telecommunication network, said UE being arranged to be served by anAccess Node in said telecommunication network. The UE comprising:

-   -   receive equipment 602 arranged for receiving a set of beams to        be monitored;    -   measure equipment 605 arranged for measuring qualities of said        received set of beams to be monitored;    -   select equipment 604 arranged for selecting a subset of said set        of beams based on said measured qualities of said received set        of beams, and    -   transmit equipment 609 arranged for transmitting measurement        data comprising measurements of qualities of said subset of        beams to said AN.

The UE 601 comprises a control unit 607 and a memory 606, which controlunit 607 is connected to the receive equipment 602, the select equipment604, the measure equipment 605 and the transmit equipment 609.

Incoming data packets or messages pass through the input terminal 603before they reach the receive equipment 602, or receive module. Outgoingdata packets or messages pass, or are sent, by the transmit equipment609, or a transmit module, via the output terminal 608.

The present invention is not limited to the embodiments as disclosedabove, and van be modified and enhanced by those skilled in the artbeyond the scope of the present invention as disclosed in the appendedclaims without having to apply inventive skills.

What is claimed is:
 1. A method of selecting a set of beams to bemonitored by a wireless device in a wireless network, said methodcomprising: receiving from the wireless device, by a network node in thewireless network, measurement data comprising measurements of qualitiesof beams observed by the wireless device, wherein said beams include atleast one beam that originates from a first access node in the wirelessnetwork and at least one beam that originates from a second access nodein the wireless network, the second access node differing from the firstaccess node; retrieving, by the network node, from a historicaldatabase, at least one measurement data from a particular wirelessdevice similar to the received measurement data, wherein the historicaldatabase comprises historical measurement data comprising measurementsof qualities of beams observed by wireless devices in said wirelessnetwork over time, selecting, by the network node, a set of beams to bemonitored by the wireless device based on said retrieved at least onemeasurement data and based on subsequent measurement data of theparticular wireless device over time in said historical database;sending to the wireless device, by the network node, an indication ofsaid selected set of beams to be monitored by the wireless device. 2.The method of claim 1, wherein said received measurement data comprisingmeasurements of qualities of beams observed by said UE comprises atleast one of any of: a signal-to-noise ratio for each of said beams; aReceived Signal Strength Indicator (RSSI) for each of said beams; aReference Signal Received Power (RSRP) for each of said beams; and aReference Signal Received Quality (RSRQ) for each of said beams.
 3. Themethod of claim 1, wherein said method further comprises the step of:storing, by the network node, said received measurement data in saidhistorical database.
 4. The method of claim 1, wherein said methodfurther comprises the steps of: determining, by the network node, basedon said retrieved at least one measurement data from said particularwireless device and based on subsequent measurement data of saidparticular wireless device over time in said historical database, thatsaid wireless device is to be handed over to a different access node insaid wireless network; and performing, by the network node, a handoverof said wireless device to said determined different access node in saidwireless network.
 5. The method of claim 1, wherein said step of sendingfurther comprises: sending a frequency parameter indicating to saidwireless device how many measurements for said selected set of beams areto be performed by said wireless device.
 6. A method of monitoring a setof beams, by a wireless device in a wireless network served by an AccessNode (AN), said method comprising the steps of: receiving, by saidwireless device, an indication of a set of beams to be monitored;measuring, by said wireless device, qualities of the set of beams;selecting, by said wireless device, a subset of said set of beams, basedon said measured qualities; and transmitting, by said wireless device,measurement data comprising measurements of qualities of only saidsubset of beams to said AN.
 7. The method of claim 6, wherein saidmeasurements of qualities comprise at least one of any of: asignal-to-noise ratio for each of said beams; a Received Signal StrengthIndicator (RSSI) for each of said beams; a Reference Signal ReceivedPower (RSRP) for each of said beams; and a Reference Signal ReceivedQuality (RSRQ) for each of said beams.
 8. The method of claim 6, whereinsaid subset of said beams consists of a fixed quantity of beams.
 9. Themethod of claim 6, wherein said receiving step comprises receiving saidset of beams from a plurality of Access Nodes.
 10. The method of claim6, further comprising receiving, in response to transmitting saidmeasurement data to said AN, an indication of another set of beams to bemonitored.
 11. A network node configured to select a set of beams to bemonitored by a wireless device in a wireless network, the network nodecomprising: a receiver configured to receive, from said wireless device,measurement data comprising measurements of qualities of beams observedby said wireless device, wherein said beams include at least one beamthat originates from a first AN in the wireless network and include atleast one beam that originates from a second AN in said wirelessnetwork; a controller configured to retrieve in a historical database,at least one measurement data from a particular wireless device similarto the received measurement data, wherein the historical databasecomprises historical measurement data comprising measurements ofqualities of beams observed by wireless devices in said wireless networkover time, and to select a set of beams to be monitored by said wirelessdevice based on said retrieved at least one measurement data and basedon subsequent measurement data of said particular wireless device overtime in said historical database; and a transmitter configured totransmit an indication of said selected set of beams to be monitored tosaid wireless device.
 12. The network node of claim 11, wherein saidreceived measurement data comprising measurements of qualities of beamsobserved by said wireless device comprises at least one of any of: asignal-to-noise ratio for each of said beams; a Received Signal StrengthIndicator (RSSI) for each of said beams; a Reference Signal ReceivedPower (RSRP) for each of said beams; and a Reference Signal ReceivedQuality (RSRQ) for each of said beams.
 13. The network node of claim 11,wherein the controller is further configured to: determine, based onsaid retrieved at least one measurement data from said particularwireless device and based on subsequent measurement data of saidparticular wireless device over time in said historical database, thatsaid wireless device is to be handed over to a different AN in saidwireless network; and perform a handover of said wireless device to saiddetermined different AN in said wireless network.
 14. The network nodeof claim 11, wherein said transmitter is further configured to: transmita frequency parameter indicating to said wireless device how manymeasurements for said selected set of beams are to be performed by saidwireless device.
 15. A wireless device arranged for monitoring a set ofbeams in a telecommunication network, said wireless device comprising: areceiver configured to receive an indication of a set of beams to bemonitored; a controller configured to measure qualities of the set ofbeams and to select a subset of said set of beams based on said measuredqualities of said received set of beams, and a transmitter configured totransmit measurement data comprising measurements of qualities of onlysaid subset of beams to said AN.
 16. The wireless device of claim 15,wherein said measurements of qualities comprise at least one of any of:a signal-to-noise ratio for each of said beams; a Received SignalStrength Indicator (RSSI) for each of said beams; a Reference SignalReceived Power (RSRP) for each of said beams; and a Reference SignalReceived Quality (RSRQ) for each of said beams.
 17. The wireless deviceof claim 15, wherein said subset of said beams consists of a fixedquantity of beams.
 18. The wireless device of claim 15, wherein saidreceiver is configured to receive said set of beams from a plurality ofANs.
 19. The wireless device of claim 15, wherein the receiver isfurther configured to receive, based on transmission of said measurementdata to said AN, an indication of another set of beams to be monitored.